OK, let's work through this together. We're starting with 399 and we're going to multiply it by 224, which means we add 399 to itself 224 times.
Step 1: 0 + 399 = 399
Step 2: 399 + 399 = 798
Step 3: 798 + 399 = 1197
Step 4: 1197 + 399 = 1596
Step 5: 1596 + 399 = 1995
Step 6: 1995 + 399 = 2394
Step 7: 2394 + 399 = 2793
Step 8: 2793 + 399 = 3192
Step 9: 3192 + 399 = 3591
Step 10: 3591 + 399 = 3990
Step 11: 3990 + 399 = 4389
Step 12: 4389 + 399 = 4788
Step 13: 4788 + 399 = 5187
Step 14: 5187 + 399 = 5586
Step 15: 5586 + 399 = 5985
Step 16: 5985 + 399 = 6384
Step 17: 6384 + 399 = 6783
Step 18: 6783 + 399 = 7182
Step 19: 7182 + 399 = 7581
Step 20: 7581 + 399 = 7980
Step 21: 7980 + 399 = 8379
Step 22: 8379 + 399 = 8778
Step 23: 8778 + 399 = 9177
Step 24: 9177 + 399 = 9576
Step 25: 9576 + 399 = 9975
Step 26: 9975 + 399 = 10374
Step 27: 10374 + 399 = 10773
Step 28: 10773 + 399 = 11172
Step 29: 11172 + 399 = 11571
Step 30: 11571 + 399 = 11970
Step 31: 11970 + 399 = 12369
Step 32: 12369 + 399 = 12768
Step 33: 12768 + 399 = 13167
Step 34: 13167 + 399 = 13566
Step 35: 13566 + 399 = 13965
Step 36: 13965 + 399 = 14364
Step 37: 14364 + 399 = 14763
Step 38: 14763 + 399 = 15162
Step 39: 15162 + 399 = 15561
Step 40: 15561 + 399 = 15960
Step 41: 15960 + 399 = 16359
Step 42: 16359 + 399 = 16758
Step 43: 16758 + 399 = 17157
Step 44: 17157 + 399 = 17556
Step 45: 17556 + 399 = 17955
Step 46: 17955 + 399 = 18354
Step 47: 18354 + 399 = 18753
Step 48: 18753 + 399 = 19152
Step 49: 19152 + 399 = 19551
Step 50: 19551 + 399 = 19950
Step 51: 19950 + 399 = 20349
Step 52: 20349 + 399 = 20748
Step 53: 20748 + 399 = 21147
Step 54: 21147 + 399 = 21546
Step 55: 21546 + 399 = 21945
Step 56: 21945 + 399 = 22344
Step 57: 22344 + 399 = 22743
Step 58: 22743 + 399 = 23142
Step 59: 23142 + 399 = 23541
Step 60: 23541 + 399 = 23940
Step 61: 23940 + 399 = 24339
Step 62: 24339 + 399 = 24738
Step 63: 24738 + 399 = 25137
Step 64: 25137 + 399 = 25536
Step 65: 25536 + 399 = 25935
Step 66: 25935 + 399 = 26334
Step 67: 26334 + 399 = 26733
Step 68: 26733 + 399 = 27132
Step 69: 27132 + 399 = 27531
Step 70: 27531 + 399 = 27930
Step 71: 27930 + 399 = 28329
Step 72: 28329 + 399 = 28728
Step 73: 28728 + 399 = 29127
Step 74: 29127 + 399 = 29526
Step 75: 29526 + 399 = 29925
Step 76: 29925 + 399 = 30324
Step 77: 30324 + 399 = 30723
Step 78: 30723 + 399 = 31122
Step 79: 31122 + 399 = 31521
Step 80: 31521 + 399 = 31920
Step 81: 31920 + 399 = 32319
Step 82: 32319 + 399 = 32718
Step 83: 32718 + 399 = 33117
Step 84: 33117 + 399 = 33516
Step 85: 33516 + 399 = 33915
Step 86: 33915 + 399 = 34314
Step 87: 34314 + 399 = 34713
Step 88: 34713 + 399 = 35112
Step 89: 35112 + 399 = 35511
Step 90: 35511 + 399 = 35910
Step 91: 35910 + 399 = 36309
Step 92: 36309 + 399 = 36708
Step 93: 36708 + 399 = 37107
Step 94: 37107 + 399 = 37506
Step 95: 37506 + 399 = 37905
Step 96: 37905 + 399 = 38304
Step 97: 38304 + 399 = 38703
Step 98: 38703 + 399 = 39102
Step 99: 39102 + 399 = 39501
Step 100: 39501 + 399 = 39900
Step 101: 39900 + 399 = 40299
Step 102: 40299 + 399 = 40698
Step 103: 40698 + 399 = 41097
Step 104: 41097 + 399 = 41496
Step 105: 41496 + 399 = 41895
Step 106: 41895 + 399 = 42294
Step 107: 42294 + 399 = 42693
Step 108: 42693 + 399 = 43092
Step 109: 43092 + 399 = 43491
Step 110: 43491 + 399 = 43890
Step 111: 43890 + 399 = 44289
Step 112: 44289 + 399 = 44688
Step 113: 44688 + 399 = 45087
Step 114: 45087 + 399 = 45486
Step 115: 45486 + 399 = 45885
Step 116: 45885 + 399 = 46284
Step 117: 46284 + 399 = 46683
Step 118: 46683 + 399 = 47082
Step 119: 47082 + 399 = 47481
Step 120: 47481 + 399 = 47880
Step 121: 47880 + 399 = 48279
Step 122: 48279 + 399 = 48678
Step 123: 48678 + 399 = 49077
Step 124: 49077 + 399 = 49476
Step 125: 49476 + 399 = 49875
Step 126: 49875 + 399 = 50274
Step 127: 50274 + 399 = 50673
Step 128: 50673 + 399 = 51072
Step 129: 51072 + 399 = 51471
Step 130: 51471 + 399 = 51870
Step 131: 51870 + 399 = 52269
Step 132: 52269 + 399 = 52668
Step 133: 52668 + 399 = 53067
Step 134: 53067 + 399 = 53466
Step 135: 53466 + 399 = 53865
Step 136: 53865 + 399 = 54264
Step 137: 54264 + 399 = 54663
Step 138: 54663 + 399 = 55062
Step 139: 55062 + 399 = 55461
Step 140: 55461 + 399 = 55860
Step 141: 55860 + 399 = 56259
Step 142: 56259 + 399 = 56658
Step 143: 56658 + 399 = 57057
Step 144: 57057 + 399 = 57456
Step 145: 57456 + 399 = 57855
Step 146: 57855 + 399 = 58254
Step 147: 58254 + 399 = 58653
Step 148: 58653 + 399 = 59052
Step 149: 59052 + 399 = 59451
Step 150: 59451 + 399 = 59850
Step 151: 59850 + 399 = 60249
Step 152: 60249 + 399 = 60648
Step 153: 60648 + 399 = 61047
Step 154: 61047 + 399 = 61446
Step 155: 61446 + 399 = 61845
Step 156: 61845 + 399 = 62244
Step 157: 62244 + 399 = 62643
Step 158: 62643 + 399 = 63042
Step 159: 63042 + 399 = 63441
Step 160: 63441 + 399 = 63840
Step 161: 63840 + 399 = 64239
Step 162: 64239 + 399 = 64638
Step 163: 64638 + 399 = 65037
Step 164: 65037 + 399 = 65436
Step 165: 65436 + 399 = 65835
Step 166: 65835 + 399 = 66234
Step 167: 66234 + 399 = 66633
Step 168: 66633 + 399 = 67032
Step 169: 67032 + 399 = 67431
Step 170: 67431 + 399 = 67830
Step 171: 67830 + 399 = 68229
Step 172: 68229 + 399 = 68628
Step 173: 68628 + 399 = 69027
Step 174: 69027 + 399 = 69426
Step 175: 69426 + 399 = 69825
Step 176: 69825 + 399 = 70224
Step 177: 70224 + 399 = 70623
Step 178: 70623 + 399 = 71022
Step 179: 71022 + 399 = 71421
Step 180: 71421 + 399 = 71820
Step 181: 71820 + 399 = 72219
Step 182: 72219 + 399 = 72618
Step 183: 72618 + 399 = 73017
Step 184: 73017 + 399 = 73416
Step 185: 73416 + 399 = 73815
Step 186: 73815 + 399 = 74214
Step 187: 74214 + 399 = 74613
Step 188: 74613 + 399 = 75012
Step 189: 75012 + 399 = 75411
Step 190: 75411 + 399 = 75810
Step 191: 75810 + 399 = 76209
Step 192: 76209 + 399 = 76608
Step 193: 76608 + 399 = 77007
Step 194: 77007 + 399 = 77406
Step 195: 77406 + 399 = 77805
Step 196: 77805 + 399 = 78204
Step 197: 78204 + 399 = 78603
Step 198: 78603 + 399 = 79002
Step 199: 79002 + 399 = 79401
Step 200: 79401 + 399 = 79800
Step 201: 79800 + 399 = 80199
Step 202: 80199 + 399 = 80598
Step 203: 80598 + 399 = 80997
Step 204: 80997 + 399 = 81396
Step 205: 81396 + 399 = 81795
Step 206: 81795 + 399 = 82194
Step 207: 82194 + 399 = 82593
Step 208: 82593 + 399 = 82992
Step 209: 82992 + 399 = 83391
Step 210: 83391 + 399 = 83790
Step 211: 83790 + 399 = 84189
Step 212: 84189 + 399 = 84588
Step 213: 84588 + 399 = 84987
Step 214: 84987 + 399 = 85386
Step 215: 85386 + 399 = 85785
Step 216: 85785 + 399 = 86184
Step 217: 86184 + 399 = 86583
Step 218: 86583 + 399 = 86982
Step 219: 86982 + 399 = 87381
Step 220: 87381 + 399 = 87780
Step 221: 87780 + 399 = 88179
Step 222: 88179 + 399 = 88578
Step 223: 88578 + 399 = 88977
Step 224: 88977 + 399 = 89376

So, 399*224 = 89376